1. Field of the Invention
Embodiments of the present invention relate to methods, media, and apparatuses for measuring a heart rate, and more particularly, to methods, media, and apparatuses for measuring a heart rate by measuring blood flow.
2. Description of the Related Art
FIG. 1 illustrates a sampling apparatus 20 for measuring heart rate based on blood flow, as implemented in embodiments of the present invention. In general, the sampling apparatus 20 measures the blood flow, oxygen saturation, or heart rate of a human body, e.g., at a finger, wrist, cheek, or earlobe, by using a photoplethysmography (PPG) sensor.
The sampling apparatus 20 includes an optical transmitting circuit 30, an optical receiving circuit 40, and a processor 50. When infrared or visible light output from the optical transmitting circuit 30 is reflected from a blood vessel, e.g., of a finger 10, the optical receiving circuit 40 detects an amplitude of the reflected light from the blood vessel of the finger 10. The amplitude of the reflected light is proportional to the blood flow in the blood vessel. The processor 50 then measures the heart rate using the reflected light detected by the optical receiving circuit 40.
However, measurement of the heart rate can be affected by the varying of contact pressure between the finger 10 and the sampling apparatus 20, the condition of a capillary vessel in the finger 10, or noise resulting from movement of the finger 10. Thereby resulting in a deteriorating of accuracy in measuring the heart rate.